Nose cap



Sept. 14, 1937. E, ZEIDLER 2,092,901

NOSE CAP Filed Nov. 9 1935 Fig. 2

36 I Inventor: 5W5: Zia/[r By (L%EQQMJ Altar/wee Patented Sept. 14, 193:7

UNITED STATES NOSE CAP Ernst Zeidler',

l rankfort-on-the-Main. Germany, assignor to Vereinigte Deutsche Metallwerke Aktiengesells'chaft, Frankfort-on-the- MaimGermany, a corporation of Germany Application November 9, 1935. Serial .No. 49,010

In Germany November 13, 1934 2 Claims.

This invention relates to means for detachably connecting a one-piece nose cap, protecting the hubs of airscrews to the hub at several points simultaneously.

The attachment and also the dismounting of airserew nose caps on and from the hub has hitherto usually been a matter taking up a good deal of time, since most of such nose caps consist of different parts which must be attached to the hub, in particular, by means of screws, bolts and the like. It has therefore been proposed to make the caps in one piece and arrange for the attachment to be as simple as possible. A known method of mounting, which is also the simplest, is by means of a clamping band or cord, but this method has the great drawback that, in the eventof the band being damagedonly in one place, the band or cord drops off and the cap is flung off the hub by the action of centrif- 20 ugal force.

The present invention aims at remedying the existing drawbacks by enabling a one-piece nose cap to be detachably connected or locked to the hub at any convenient number of points, by a turn of the hand.

To this end, according to the invention, a.

rotatable or expandible locking means, carrying all the fixing members jointly, is indirectly or directly connected to, the hub.

In the case of nose caps with a plurality of parts, it is known to connect such parts together, at several points simultaneously, by locking devices, but in these cases precisely the problem on which the present invention is based remains unsolved, namely the provision of an easily operated method of connection and release between a one-piece nose cap and the airscrew, or its hub.

The design of the detachable connection of the present invention may vary in point of detail, the sole proviso being that the foregoing condition is fulfilled. For example, it may be established by means of a rotatable ring, engaging by means of slots, with corresponding pins on the cap, or conversely, by means of pins engaging in slots in the cap and thus enabling the looking to be effected at any number of points simultaneously. These pins which look the cap may also be designed as rotatable or sliding bolts, controlled by the rotatable ring. However, it is also possible to interconnect articulated leverlike bolts adapted to be shot conjointly and controlled by a push bar in such a manner that said bolts can be brought into engagement with corresponding slots in the one-piece cap.

A special advantage is obtained by combining with the locking arrangement, safety devices for securing same and'coming irito operation at the same time as the former.

In order more clearly to understand the invention, reference is made to the accompanying drawing which illustrates diagrammatically and by way of example, several embodiments thereof.

In said drawing:

} Fig. 1 illustrates a side elevational view, somewhat fragmentary and having parts cut away, of an exemplary embodiment of the invention in which a nose cap is provided with a plurality of pins engaging slots in a rotatable ring;

Fig. 2 depicts a vertical sectional view, also fragmentary, taken on line 2-2 of Fig. 1;

' Fig. 3 shows a longitudinal and fragmentary sectional view of a modified embodiment of the invention in which a plurality of slots is provided in the nose cap, and a rotatable ring carrying a pin for each of said slots co-operates with said nose cap;

Fig. 4 is a fragmentary bodiment illustrated in Fig. 3;

Fig. 5 illustrates a front elevational view, somewhat fragmentary and having parts in section, of another embodiment of the invention including a pivoted bolt lever engaging through corresponding openings in the trolled by a rotatable ring;

Fig. 6 depicts a vertical sectional view taken on line 66 of Fig. 5;

Fig. 7 shows a front elevational view somewhat fragmentary and having parts in section, of a further embodiment of the invention embodying radially displaceable bolt levers;

Fig. 8 is a vertical sectional view taken on line 88 of Fig. 7; and

Fig. 9 shows another arrangement embodying the principles of the invention in which pivoted expandible bolt levers are. provided capable of being brought into and out of engagement with slots in the nose cap.

In the embodiment according to Figs. 1 and 2, a plate I, the rim of which is bent round at an angle at I', in the direction of the engine is secured to the body of the hub 3 of the airscrew, for example by means of screws 2. Below the annular flange I, of the plate I, and bearing against the latter, is a flat ring 4 provided with holes 9 which merg on the one side, into slots III. The plate I is also responding to the holes 9 in the ring 4.

The one-piece nose cap 5, which is suitably cut away for the passage of the air-screw blades,

bears, by means of its inwardly turned rim plan view of the emnose cap and conprovided with holes cor-' on the plate I, secured to the hub 3 on the side remote from the ring 4. The 'nose cap 5 is centered by means of a ring 1, surroundin (for example, riveted on) the annular flange I, and

5 the cap is supported by means of a plate 5' mounted on the inside of the cap 5 and adapted to slip over the outer end of the hub 3. The rim 6 of the nose cap carries pins 8 which-are provided with annular grooves and coact with the 10 holes 9 in the ring 4 and plate I. A lug II, on the ring, and serving as a handle for rotatively displacing the ring 4, protrudes through corresponding slots in the annular flange I' and ring 1.

In assembling the cap 5, the pins 8 attached thereto penetrate through the holes 9 in the plate I and ring 4, said holes being at first in alignment. Rotatively displacing the ring 4 by means of the lug I I is all that is now needed to bring the lateral slots III into engagement with the grooves in the pins 8, and thus lock the cap 5 at any convenient number of points, in accordance with the number of pins 8 and openings 9, III provided. To release the nose cap 5, the ring 4 is turned in the oppo- 5 site direction until the pins 8 come out of the slots I0, and the holes 9 in the ring 4 are again in alignment with the corresponding holes in the plate I, whereupon the nose cap can be dismounted without any further manipulation.

In the example according to Figs. 8 and 4, the outer ring I2 which centres the nose cap I6 on the annular flange of the plate I3 attached to the hub, is adapted to be rotatively displaced by means of the handle I2, and is provided with the locking pins I4 which are passed inwards through longitudinal holes I5 in the annular flange of the plate I3. The length of the holes I5 determines the extent to which the ring I2 can be rotated. The cap I6 is provided with bayonet-catch slots 0 I1 on the rim adapted to be inserted between I2 and I. In addition, the annular flange of the plate I3 carries a pin I3 on which fits the slot IS in the nose cap. As is evident from Fig. 4, from which the outer ring I2 is omitted all that is necessary, after the cap I6 has been slipped into place, is to turn the ring I2 so that its pin I4 enters the bayonet-catch slot I1, and thereby lock the nose cap at any convenient number of points. Figs. 3 and 4 also show a safety catch which comes into operation at the same time as the looking device. Secured (for example, riveted) on the annular flange of the plate I3, at I9, is a flat spring I8 carrying a stud. 20. Directly the ring l2 has arrived in the locking position, said stud 20 springs through the annular flange of the plate I3 into a hole in the ring I2 and thus prevents the latter from unintentional reversion. In order to release the cap IS, the catch stud 20 must first be pushed inwards, before the ring I2 can be turned back;

According to Figs. 5 and 6, the plate 2|, which is attached to the hub and over the marginal flange of which the cap 21 is slipped, is provided with rotatably mounted or pivoted levers or bolts 22, the one arm of which is engaged by pins 23, seated on the ring 24, which is adapted to be rotated by means of the handle 24',.said pins enabling the other arm to enter at 25 corresponding slots26 in the cap 21, directly the ring 24 is rotatively displaced in the one direction by means of the handle 24'. The broken lines in Fig. 6 represent the provided lever or bolt 22 in the released position.

I In the example shown in Figs. 7 and 8, the looking of the cap 34 with the plate 28 attached to the hub is effected by means of radially displaceable bolts or push bars 29 which engage, by means of pins 30, in oblique slots 3I in the ring 32 rotatively displaceable by the handle 32, and are guided by fillets 28 attached to the plate 28. When the ring 32 is suitably rotated, the ends 33 of the bars 29 enter openings in the cap 34 and lock the latter as shown in Figs. '1 and 8. For the release, the ring 32 is turned the other way, the bars 29 being so controlled by the oblique slots 3I that their ends 33 release the cap 34.

In the example according to Fig. 9, lever mechanism is provided for locking the cap 49. This mechanism comprises the levers 35 which, at the ends provided with the locking noses 36-ior example, on the plate (not shown) attached to the hub of the airscrew-are rotatably mounted, the other end being provided with slots 31. Levers 35 are pivoted in pins 4I. Slots 31 are engaged by pins 38 seated on the bar 39- which is adapted to be moved in the longitudinal direction by hand. On said bar being moved in the direction of the arrow, the levers 35 are turned through the agency of the pin-and-slot guides 31, 38, so as to bring their locking noses out of engagement with the nose cap 40.

I claim:

1. In an aircraft. propeller, the combination I comprising an airscrew, a hub associated with said airscrew, a one-piece nose cap covering said hub, a plate-like supporting member having one of its ends rigidly connected to said hub and having a surface at its other end conforming to the terminal surface of said nose cap, mutually engageable fixing means including pins and slots on said supporting member; and on said nose cap adapted to retain said nose cap in a predetermined position,

and a rotatably displaceable locking ring having tapered slots therein cooperating with said pins, I

said ring being adapted to be displaced from an inoperative into an operative position to instantaneously locksaid pins and said nose cap.

2. In an aircraft propeller, the combination comprising an airscrew, a hub associated with said airscrew, a. one-piece nose cap covering said hub, a supporting member rigidly fastened-to said hub and having a supporting surface con forming to the terminal portion of said nose cap, fixing means associated with said supporting surface and said terminal portion adapted to engage each other in a predetermined position of said nose cap, manually operable elements including a rotatably displaceable common locking ringadapted to be displaced from an inoperative into an operative position to lock said fixing means in mutually engaging position, and safety catch means automatically engaging said locking means in the operative position thereof to prevent accidental release of said fixing means.

ERNST ZEIDLER. 

